Johannes Christiaan Jan ("Han") Lammers (10 September 1931 – 5 July 2000) was a Dutch journalist and politician who served as the first Queen's Commissioner of Flevoland from 1986 to 1996.

A member of the Labor Party, he previously served as Mayor of Almere from 1984 to 1986, Landdrost of the Southern IJsselmeerpolders from 1976 to 1984, and as an Alderman of Amsterdam from 1970 to 1976.

After his father's arrest in 1941, Lammers and his mother moved to Aalten, where he attended school and took organ lessons, later becoming one of his greatest passions.

Lammers and his family returned to The Hague following the end of the German occupation of the Netherlands, where he attended the Christelijk Gymnasium, graduating in 1951.

As mayor, Lammers sought to develop Almere into a functioning city, and increased the involvement of citizens within the local government.

He believed that Flevoland would become an important province in relation to the rest of the Netherlands, particularly in its potential to act as a clean slate for spatial planning.

[4] Following his retirement, Lammers devoted his time to playing the organ, but briefly served as the acting mayor of Groningen in 1998.